Re: [PATCH 4.19] dmaengine: at_hdmac: Fix memory leak

[Greg KH]

On Wed, Sep 23, 2020 at 08:19:18AM +0000, Tudor.Ambarus@xxxxxxxxxxxxx wrote:
> On 9/23/20 11:13 AM, Tudor.Ambarus@xxxxxxxxxxxxx wrote:
> > Hi, Pavel,
> > 
> > On 9/20/20 11:28 AM, Pavel Machek wrote:
> >> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> >>
> >> This fixes memory leak in at_hdmac. Mainline does not have the same
> >> problem.
> >>
> >> Signed-off-by: Pavel Machek (CIP) <pavel@xxxxxxx>
> >>
> >> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> >> index 86427f6ba78c..0847b2055857 100644
> >> --- a/drivers/dma/at_hdmac.c
> >> +++ b/drivers/dma/at_hdmac.c
> >> @@ -1714,8 +1714,10 @@ static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
> >>         atslave->dma_dev = &dmac_pdev->dev;
> >>
> >>         chan = dma_request_channel(mask, at_dma_filter, atslave);
> >> -       if (!chan)
> >> +       if (!chan) {
> >> +               kfree(atslave);
> >>                 return NULL;
> >> +       }
> > 
> > Thanks for submitting this to stable. While the fix is good, you can instead
> > cherry-pick the commit that hit upstream. In order to do that cleanly on top
> > of v4.19.145, you have to pick two other fixes:
> > 
> > commit a6e7f19c9100 ("dmaengine: at_hdmac: Substitute kzalloc with kmalloc")
> > commit 3832b78b3ec2 ("dmaengine: at_hdmac: add missing put_device() call in at_dma_xlate()")
> > commit a6e7f19c9100 ("dmaengine: at_hdmac: Substitute kzalloc with kmalloc")
> 
> this last commit should have been
> commit e097eb7473d9 ("dmaengine: at_hdmac: add missing kfree() call in at_dma_xlate()")
> 
> bad copy and paste :)

So are all 3 of those needed on both 5.4.y and 4.19.y to resolve this
issue?

thanks,

greg k-h